Chapter 14: Brain & Cranial Nerves Flashcards
nervous system develops from the ____
ectoderm
During the 3rd week of development of what happens
the neural plate forms along the dorsal midline and thickens
What happens in the 4th week of development?
a hollow channel is created called the neural tube
3 anterior dilations of the neural tube
- forebrain
- midbrain
- hindbrain
forebrain
prosencephalon
mindbrain
mesencephalon
hindbrain
rhombencephalon
forebrain splits into
telencephalon and diencephalon
hindbrain splits into
metencephalon and myelencephalon
metencephalon
pons & cerebellum
myelencephalon
medulla oblongata
___ ___ separates the 2 cerebral hemispheres
falx cerebri
meningitis
inflammation of the meninges
choroid plexus
spongy mass of blood capillaries on the floor of each ventricle
ependyma
produces cerebriospinal fluid
CSF
clear colorless liquid that fills the ventricles & canals of CNS
which ventricle has then most CSF?
right and left lateral ventricles
circulation of the CSF (6)
- secreted by lateral ventricles
- flows through intervertebral foramina into 3rd ventricle (add more CSF)
- down the cerebral aqueduct into 4th ventricle (add more CSF)
- fills the central canal & flows out of 3 pores
- fills arachnoid space and bathes external surface of brain
- arachnoid villi reabsorb CSF
Functions of CSF (3)
buyoancy
protection
chemical stability
nervous system requires a lot of ___ and _____
glucose and oxygen
10 sec interruption of blood flow
1-2 min interruption of blood flow
loss of consciousness
sign impairment of neural function
what 2 points of entry must be guarded by the BBB
blood capillaries throughout the brain tissue
capillaries of choroid plexus
what is the BBB highly permeable to?slightly permeable?
water, glu, oxygen, CO2, alcohol, etc
Na, K, Cl
circumventricular organs
places in the third and fourth ventricles where the barrier is absent
the medulla oblongata pyramids?
resembles baseball bats
the medulla oblongata olives? (2)
a prominent bulge lateral to each pyramid
relay centers for signals to cerebellum
which cranial nerves begin or end in the medulla oblongata?
9,10,11,12
functions of medulla oblongata (4)
cardiac center
vasomotor center
respiratory center
reflex center
where can the reticular formation be found
midbrain, pons, medulla oblongata
pons and cerebellum develop from?
metencephalon of hindbrain
cerebral peduncles
connect the cerebellum to pons, mid brain, medulla oblongata
which cranial nerves are found on pons
5, 6, 7, 8
mesencephalon (3)
midbrain
contains the cerebral aqueduct
contains cranial nerves 2 and 4
what are the 3 main components of cerebral peduncles?
tegmentum
substantia nigra
cerebral crus
reticular formation
loosely organized gray matter that runs throughout the brainstem
5 networks of reticular formations?
somatic motor control cardiovascular control pain modulation sleep & consciousness habituation
the largest part of the hindbrain and second largest part of the brain
cerebellum
which structure of the brain contains more than half of all brain neurons
cerebellum
inferior?superior?middle peduncles?
inferior: medulla oblongata
superior: midbrain
middle: pons
functions of cerebellum (2)
motor control & motion memory
diencephalon contains what 3 derivative?
thalamus
hypothalamus
epithalamus
functions of thalamus
involved in memory; emotional functions of the limbic system
function of hypothalamus
homeostasis
epithalamus contains
pineal gland
frontal lobe
voluntary motor functions (motivation, foresight, planning, memory)
parietal lobe
receives and integrates sensory info
occipital lobe
primary visual center of brain
temporal lobe
areas for hearing, smell, learning
insula region
understanding spoken language, taste and sensory info
Most of the volume of the cerebrum is what?
white matter (lots of axons)
3 types of tracts in the cerebral white matter?
projection (cerebrum to the rest of the body)
commissural
association (long or short)
cerebral cortex
neocortex (6 layers)
layer covering the surface of the hemispheres
what cells can be found in the cerebral cortex? (2)
stellate cells & pyramidal cells
basal nucleu
masses of cerebral gray matter buried deep in white matter
limbic system
important center for emotions and learning
hippocampus
memory
amygdala
emotions
limbic system has structures for centers of _____ and _____
gratification (pleasure or reward) and aversion (fear and sorrow)
higher brain functions involve interactions between ___ ___ and ___, _____, and _____
cerebral cortex, basal nuclei, brainstem and cerebellum
alpha waves (2)
awake and resting with eyes closed
stage 1 of sleep
beta waves
eyes open and performing mental task
theta waves
drowsy or sleeping adults (if awake under emotional stress)
delta waves
deep sleep in adults
electroencephalogram (EEG)
monitors surface electrical activity of the brain waves
stage 2 of sleep
pass into light sleep
stage 3 of sleep (3)
theta & delta waves
muscles relax
vital signs fall
stage 4 of sleep (3)
slow wave sleep
muscles are very relaxed
difficult to wake up
REM
rapid eye movement (eyes oscillate back and forth)
cognition
the range of mental processes by which we acquire and use knowledge completed by association areas of cerebral cortex
info management entails (3):
learning
memory
forgetting
werneike area
permits recognition of spoken & written language to formulate phrases then passes it on to broca’s area
broca’s area
generates motor program to lips tongue and cheeks
aprosody
flat emotionless speech
aphasia
any language deficit from lesions in same hemisphere containing the werneikes & broca area
cerebral lateralization (2)
dif in the structure & function of the cerebral hemisphere
develops with age (increased in males)
primary somesthetic(general senses) cortex is the cortex of the ___ ____
postcentral gyrus
sensory homunculus
upside down sensory map of the contralateral side of the body
we have lots of sensation where?
in the face
primary motor area is transmitted where
precentral gyrus
cranial I
olfactory
sense of smell
cranial II
optic nerve
provides vision
cranial III
oculomotor
extrinistic muscles of the eye
cranial IV
trochlear
eye movement
cranial V
trigeminal
largest
important for sensory nerve of face
cranial VI
abducens
eye movement
cranial VII
facial
facial expressions
cranial VIII
vestibulocochlear
hearing and equilibrium
cranial IX
glossopharyngeal
swallowing, salivation, gagging
cranial X
vagus nerve
major role in cardiac, pulmonary, digestive, urinary function
cranial XI
accessory
head neck and should movement
cranial XII
hypoglossal
tongue movements for speech and food manipulation
